/Engine/Source/Runtime/Core/Public/Misc/Compression.h
Thread-safe abstract compression routine to query memory requirements for a compression operation. This is the minimize size to allocate the buffer for CompressMemory (encoding). Use GetMaximumCompressedSize at decode to know how large a compressed buffer may be.
The maximum possible bytes needed for compression of data buffer of size UncompressedSize
static int32 CompressMemoryBound ( [FName](API\Runtime\Core\UObject\FName) FormatName, int32 UncompressedSize, ECompressionFlags Flags, int32 CompressionData )